The purpose of this analysis is to determine what factors explain the difference in price between an economy ticket and a premium-economy airline ticket.

Summary Statistics

summary(airlines)
##       Airline      Aircraft   FlightDuration   TravelMonth
##  AirFrance: 74   AirBus:151   Min.   : 1.250   Aug:127    
##  British  :175   Boeing:307   1st Qu.: 4.260   Jul: 75    
##  Delta    : 46                Median : 7.790   Oct:127    
##  Jet      : 61                Mean   : 7.578   Sep:129    
##  Singapore: 40                3rd Qu.:10.620              
##  Virgin   : 62                Max.   :14.660              
##       IsInternational  SeatsEconomy    SeatsPremium    PitchEconomy  
##  Domestic     : 40    Min.   : 78.0   Min.   : 8.00   Min.   :30.00  
##  International:418    1st Qu.:133.0   1st Qu.:21.00   1st Qu.:31.00  
##                       Median :185.0   Median :36.00   Median :31.00  
##                       Mean   :202.3   Mean   :33.65   Mean   :31.22  
##                       3rd Qu.:243.0   3rd Qu.:40.00   3rd Qu.:32.00  
##                       Max.   :389.0   Max.   :66.00   Max.   :33.00  
##   PitchPremium    WidthEconomy    WidthPremium    PriceEconomy 
##  Min.   :34.00   Min.   :17.00   Min.   :17.00   Min.   :  65  
##  1st Qu.:38.00   1st Qu.:18.00   1st Qu.:19.00   1st Qu.: 413  
##  Median :38.00   Median :18.00   Median :19.00   Median :1242  
##  Mean   :37.91   Mean   :17.84   Mean   :19.47   Mean   :1327  
##  3rd Qu.:38.00   3rd Qu.:18.00   3rd Qu.:21.00   3rd Qu.:1909  
##  Max.   :40.00   Max.   :19.00   Max.   :21.00   Max.   :3593  
##   PricePremium    PriceRelative      SeatsTotal  PitchDifference 
##  Min.   :  86.0   Min.   :0.0200   Min.   : 98   Min.   : 2.000  
##  1st Qu.: 528.8   1st Qu.:0.1000   1st Qu.:166   1st Qu.: 6.000  
##  Median :1737.0   Median :0.3650   Median :227   Median : 7.000  
##  Mean   :1845.3   Mean   :0.4872   Mean   :236   Mean   : 6.688  
##  3rd Qu.:2989.0   3rd Qu.:0.7400   3rd Qu.:279   3rd Qu.: 7.000  
##  Max.   :7414.0   Max.   :1.8900   Max.   :441   Max.   :10.000  
##  WidthDifference PercentPremiumSeats
##  Min.   :0.000   Min.   : 4.71      
##  1st Qu.:1.000   1st Qu.:12.28      
##  Median :1.000   Median :13.21      
##  Mean   :1.633   Mean   :14.65      
##  3rd Qu.:3.000   3rd Qu.:15.36      
##  Max.   :4.000   Max.   :24.69
describe(airlines)
##                     vars   n    mean      sd  median trimmed     mad   min
## Airline*               1 458    3.01    1.65    2.00    2.89    1.48  1.00
## Aircraft*              2 458    1.67    0.47    2.00    1.71    0.00  1.00
## FlightDuration         3 458    7.58    3.54    7.79    7.57    4.81  1.25
## TravelMonth*           4 458    2.56    1.17    3.00    2.58    1.48  1.00
## IsInternational*       5 458    1.91    0.28    2.00    2.00    0.00  1.00
## SeatsEconomy           6 458  202.31   76.37  185.00  194.64   85.99 78.00
## SeatsPremium           7 458   33.65   13.26   36.00   33.35   11.86  8.00
## PitchEconomy           8 458   31.22    0.66   31.00   31.26    0.00 30.00
## PitchPremium           9 458   37.91    1.31   38.00   38.05    0.00 34.00
## WidthEconomy          10 458   17.84    0.56   18.00   17.81    0.00 17.00
## WidthPremium          11 458   19.47    1.10   19.00   19.53    0.00 17.00
## PriceEconomy          12 458 1327.08  988.27 1242.00 1244.40 1159.39 65.00
## PricePremium          13 458 1845.26 1288.14 1737.00 1799.05 1845.84 86.00
## PriceRelative         14 458    0.49    0.45    0.36    0.42    0.41  0.02
## SeatsTotal            15 458  235.96   85.29  227.00  228.73   90.44 98.00
## PitchDifference       16 458    6.69    1.76    7.00    6.76    0.00  2.00
## WidthDifference       17 458    1.63    1.19    1.00    1.53    0.00  0.00
## PercentPremiumSeats   18 458   14.65    4.84   13.21   14.31    2.68  4.71
##                         max   range  skew kurtosis    se
## Airline*               6.00    5.00  0.61    -0.95  0.08
## Aircraft*              2.00    1.00 -0.72    -1.48  0.02
## FlightDuration        14.66   13.41 -0.07    -1.12  0.17
## TravelMonth*           4.00    3.00 -0.14    -1.46  0.05
## IsInternational*       2.00    1.00 -2.91     6.50  0.01
## SeatsEconomy         389.00  311.00  0.72    -0.36  3.57
## SeatsPremium          66.00   58.00  0.23    -0.46  0.62
## PitchEconomy          33.00    3.00 -0.03    -0.35  0.03
## PitchPremium          40.00    6.00 -1.51     3.52  0.06
## WidthEconomy          19.00    2.00 -0.04    -0.08  0.03
## WidthPremium          21.00    4.00 -0.08    -0.31  0.05
## PriceEconomy        3593.00 3528.00  0.51    -0.88 46.18
## PricePremium        7414.00 7328.00  0.50     0.43 60.19
## PriceRelative          1.89    1.87  1.17     0.72  0.02
## SeatsTotal           441.00  343.00  0.70    -0.53  3.99
## PitchDifference       10.00    8.00 -0.54     1.78  0.08
## WidthDifference        4.00    4.00  0.84    -0.53  0.06
## PercentPremiumSeats   24.69   19.98  0.71     0.28  0.23

Variation of Number of Seats with Airlines

par(mfrow=c(1,2))
boxplot(SeatsEconomy~Airline,data=airlines,col=c("yellow","red","blue","green","grey","purple"),main="Economy Seats vs Airlines",ylab="Airlines",xlab="Number of Seats",horizontal=TRUE)
boxplot(SeatsPremium~Airline,data=airlines,col=c("yellow","red","blue","green","grey","purple"),main="Premium Economy Seats vs Airlines",ylab="Airlines",xlab="Number of Seats",horizontal=TRUE)

par(mfrow=c(1,1))
aggregate(airlines$SeatsEconomy,by=list(Airlines=airlines$Airline),median)
##    Airlines   x
## 1 AirFrance 200
## 2   British 243
## 3     Delta 126
## 4       Jet 138
## 5 Singapore 184
## 6    Virgin 198
aggregate(airlines$SeatsPremium,list(Airlines=airlines$Airline),median)
##    Airlines  x
## 1 AirFrance 24
## 2   British 40
## 3     Delta 20
## 4       Jet 16
## 5 Singapore 28
## 6    Virgin 38

Its clear from the above plots and tables that the number of Premium economy seats are way less than the economy seats in any given airline.Therefore, number of seats may be a possible contributor to the difference in ticket prices.

Correlation Between number of Seats and Difference in Seat prices

cor(airlines[, c(6,7,14)])
##               SeatsEconomy SeatsPremium PriceRelative
## SeatsEconomy   1.000000000   0.62505659   0.003956939
## SeatsPremium   0.625056587   1.00000000  -0.097196009
## PriceRelative  0.003956939  -0.09719601   1.000000000

Analysing the Pitch Difference

par(mfrow=c(1,3))
plot(airlines$PitchPremium ,airlines$PitchEconomic,cex=0.5, main = "Economic Pitch vs Premium Pitch",ylab = "Economic Pitch",xlab = "Premium Economic Pitch",col="red")
boxplot(airlines$PitchEconomy,col="yellow",main="Economic Seat Pitch",ylab= "Seat Pitch(inches)", xlab="Economic Seats")
boxplot(airlines$PitchPremium,col="green",main="Premium Economic Seat Pitch",ylab="Seat Pitch(inches)",xlab="Premium Economic Seats")

par(mfrow=c(1,1))

The Plot represents the difference in the pitch (in inches) of the the economic and premium economic seats. As is clear the premium economic seat pitches are way longer than that of the corresponding economic seat pitches.

The second plot is a boxplot of The Economic Seat Pitch median and outliers. The median is:

median(airlines$PitchEconomy)
## [1] 31

The third is a boxplot that shows the median of the Premium Economic Seat Pitch.The median is:

median(airlines$PitchPremium)
## [1] 38

From the above analysis, its clear that the Premium Economic Seat Pitch is larger than the Economic Seat Pitch. Thus, pitch may be a possible contributer to the Difference in prices.

Correlation between Pitch Of Seats and Price of Tickets

cor(airlines[, c(8,9,14)])
##               PitchEconomy PitchPremium PriceRelative
## PitchEconomy     1.0000000   -0.5506062    -0.4230220
## PitchPremium    -0.5506062    1.0000000     0.4175391
## PriceRelative   -0.4230220    0.4175391     1.0000000

Analysing the Width Difference

par(mfrow=c(1,3))
plot(airlines$WidthPremium ,airlines$WidthEconomic,cex=0.5, main = "Economic Width vs Premium Width",ylab = "Economic Width",xlab = "Premium Economic Width",col="red")
boxplot(airlines$WidthEconomy,col="yellow",main="Economic Seat Width",ylab= "Seat Width(inches)", xlab="Economic Seats")
boxplot(airlines$WidthPremium,col="green",main="Premium Economic Seat Width",ylab="Seat Width(inches)",xlab="Premium Economic Seats")

par(mfrow=c(1,1))

The Plot represents the difference in the width (in inches) of the the economic and premium economic seats. As is clear the premium economic seat width are way longer than that of the corresponding economic seat pitches.

The second plot is a boxplot of The Economic Seat Width median and outliers. The median is:

median(airlines$WidthEconomy)
## [1] 18

The third is a boxplot that shows the median of the Premium Economic Seat Width.The median is:

median(airlines$WidthPremium)
## [1] 19

From the above analysis, its clear that the Premium Economic Seat Width is larger than the Economic Seat Width. Thus, Width may be a possible contributer to the Difference in prices.

Correlation between Pitch Of Seats and Price of Tickets

cor(airlines[, c(10,11,14)])
##               WidthEconomy WidthPremium PriceRelative
## WidthEconomy    1.00000000   0.08191873   -0.04396116
## WidthPremium    0.08191873   1.00000000    0.50424759
## PriceRelative  -0.04396116   0.50424759    1.00000000

Analysis of Ticket prices

First lets see the distribution of ticket price among the two categories.

par(mfrow=c(1,2))
hist(airlines$PriceEconomy,breaks = 20,col="grey", main = "Economy Ticket Prices",ylab = "Frequency",xlab = "Ticket Price")

hist(airlines$PricePremium,breaks = 20,col="grey", main = "Premium Economy Ticket Prices",ylab = "Frequency",xlab = "Ticket Price")

par(mfrow=c(1,1))

As is clear from the above two histograms, a Large number of premium economic seats are much more expensive than the economic seats.

For a clear view of it, here’s a plot between the Ticket prices.

plot(airlines$PriceEconomy,airlines$PricePremium,
cex=0.8,main = "Ticket Prices", ylab="Premium Economic Ticket Price",xlab="Economic Ticket Price",col="blue")
abline(h=mean(airlines$PricePremium), col="dark blue", lty="dotted")
abline(v=mean(airlines$PriceEconomy), col="dark blue", lty="dotted")
abline(lm(airlines$PricePremium ~ airlines$PriceEconomy),col="green")

The horizontal line is the mean line of Premium Economic ticket price. The vertical line represents the mean of Economic ticket price. The green line is the best fit line between the two.

Variation with Month of travel

Lets also analyse how the prices vary with the month of travel.

First lets check it out for economic seats.

 barchart(PriceEconomy ~ TravelMonth, data=airlines, 
 col=c("gray95", "gray50"),main="Economic Ticket Price",
 ylab="Price",xlab="Travel Month")

Now for premium economic seats.

 barchart(PricePremium ~ TravelMonth, data=airlines, 
 col=c("gray95", "gray50"),main="Premium Economic Ticket Price",
 ylab="Price",xlab="Travel Month")

Correlation of Different Variables with Differnce in Price

A correlation Matrix is a good way to anayle the strength of dependencies.

cor(airlines[,c(6:14,18)])
##                     SeatsEconomy SeatsPremium PitchEconomy PitchPremium
## SeatsEconomy         1.000000000  0.625056587   0.14412692  0.119221250
## SeatsPremium         0.625056587  1.000000000  -0.03421296  0.004883123
## PitchEconomy         0.144126924 -0.034212963   1.00000000 -0.550606241
## PitchPremium         0.119221250  0.004883123  -0.55060624  1.000000000
## WidthEconomy         0.373670252  0.455782883   0.29448586 -0.023740873
## WidthPremium         0.102431959 -0.002717527  -0.53929285  0.750259029
## PriceEconomy         0.128167220  0.113642176   0.36866123  0.050384550
## PricePremium         0.177000928  0.217612376   0.22614179  0.088539147
## PriceRelative        0.003956939 -0.097196009  -0.42302204  0.417539056
## PercentPremiumSeats -0.330935223  0.485029771  -0.10280880 -0.175487414
##                     WidthEconomy WidthPremium PriceEconomy PricePremium
## SeatsEconomy          0.37367025  0.102431959   0.12816722   0.17700093
## SeatsPremium          0.45578288 -0.002717527   0.11364218   0.21761238
## PitchEconomy          0.29448586 -0.539292852   0.36866123   0.22614179
## PitchPremium         -0.02374087  0.750259029   0.05038455   0.08853915
## WidthEconomy          1.00000000  0.081918728   0.06799061   0.15054837
## WidthPremium          0.08191873  1.000000000  -0.05704522   0.06402004
## PriceEconomy          0.06799061 -0.057045224   1.00000000   0.90138870
## PricePremium          0.15054837  0.064020043   0.90138870   1.00000000
## PriceRelative        -0.04396116  0.504247591  -0.28856711   0.03184654
## PercentPremiumSeats   0.22714172 -0.183312058   0.06532232   0.11639097
##                     PriceRelative PercentPremiumSeats
## SeatsEconomy          0.003956939         -0.33093522
## SeatsPremium         -0.097196009          0.48502977
## PitchEconomy         -0.423022038         -0.10280880
## PitchPremium          0.417539056         -0.17548741
## WidthEconomy         -0.043961160          0.22714172
## WidthPremium          0.504247591         -0.18331206
## PriceEconomy         -0.288567110          0.06532232
## PricePremium          0.031846537          0.11639097
## PriceRelative         1.000000000         -0.16156556
## PercentPremiumSeats  -0.161565556          1.00000000

A visual correlation is of course easy to understand.

 corrgram(airlines[,c(6:14,18)], order=FALSE, lower.panel=panel.shade,
          upper.panel=panel.pie, text.panel=panel.txt,
          main="Corrgram of store variables")

Hypothesis

Let the hypothesis be: The difference of prices of economic and premium economic seats is affected by percentage of premium seats, difference in pitch and difference in width of the seats.

Pearson’s Correlation Test on Relative Price along with Percentage of Premium seats

 cor.test(airlines$PriceRelative,airlines$PercentPremiumSeats)
## 
##  Pearson's product-moment correlation
## 
## data:  airlines$PriceRelative and airlines$PercentPremiumSeats
## t = -3.496, df = 456, p-value = 0.0005185
## alternative hypothesis: true correlation is not equal to 0
## 95 percent confidence interval:
##  -0.24949885 -0.07098966
## sample estimates:
##        cor 
## -0.1615656

The p-value<0.05. This implies that percentage of premium seats is significantly correlated with relative price of tickets.

Pearson’s Correlation Test on Relative Price along with Pitch difference

 cor.test(airlines$PriceRelative,airlines$PitchDifference)
## 
##  Pearson's product-moment correlation
## 
## data:  airlines$PriceRelative and airlines$PitchDifference
## t = 11.331, df = 456, p-value < 2.2e-16
## alternative hypothesis: true correlation is not equal to 0
## 95 percent confidence interval:
##  0.3940262 0.5372817
## sample estimates:
##       cor 
## 0.4687302

The p-value<0.05. This implies that Pitch difference is significantly correlated with relative price of tickets.

Pearson’s Correlation Test on Relative Price along with Width difference

 cor.test(airlines$PriceRelative,airlines$WidthDifference)
## 
##  Pearson's product-moment correlation
## 
## data:  airlines$PriceRelative and airlines$WidthDifference
## t = 11.869, df = 456, p-value < 2.2e-16
## alternative hypothesis: true correlation is not equal to 0
## 95 percent confidence interval:
##  0.4125388 0.5528218
## sample estimates:
##       cor 
## 0.4858024

The p-value<0.05. This implies that Width difference is significantly correlated with relative price of tickets.

Scatterplot Matrix

A visual measure of correlation help in undersatnding.

scatterplotMatrix(formula = ~ PriceRelative + PitchDifference + WidthDifference + PercentPremiumSeats, cex=0.6,
                       data=airlines, diagonal="density")

Linear Regression

Let the regressiomn equation be:

PriceRelative = b0 + b1PercentPremiumSeats + b2PitchDifference + b3WidthDifference+ ??

Now the analysis:

m1<-lm(PriceRelative~  PercentPremiumSeats + PitchDifference + WidthDifference,data = airlines)
summary(m1)
## 
## Call:
## lm(formula = PriceRelative ~ PercentPremiumSeats + PitchDifference + 
##     WidthDifference, data = airlines)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.88643 -0.29471 -0.05005  0.19013  1.17157 
## 
## Coefficients:
##                      Estimate Std. Error t value Pr(>|t|)    
## (Intercept)         -0.031508   0.097220  -0.324    0.746    
## PercentPremiumSeats -0.005764   0.003971  -1.451    0.147    
## PitchDifference      0.064596   0.016171   3.994 7.56e-05 ***
## WidthDifference      0.104782   0.024813   4.223 2.92e-05 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.3882 on 454 degrees of freedom
## Multiple R-squared:  0.2627, Adjusted R-squared:  0.2579 
## F-statistic: 53.93 on 3 and 454 DF,  p-value: < 2.2e-16

From the regression, it can be observed that Percentage of premium seats has no significant(p>0.05) affect on the relative difference in prices of the two categories.

Whereas Pitch difference and Width difference are significant enough(p<0.05).

Coefficients

The coefficients of the equation are:

m1$coefficients
##         (Intercept) PercentPremiumSeats     PitchDifference 
##        -0.031508119        -0.005764216         0.064596209 
##     WidthDifference 
##         0.104781532

Confident Intervals of Coefficients

The confidence intervals are:

confint(m1)
##                           2.5 %      97.5 %
## (Intercept)         -0.22256544 0.159549200
## PercentPremiumSeats -0.01356861 0.002040183
## PitchDifference      0.03281620 0.096376213
## WidthDifference      0.05601923 0.153543836

Visualising Coefficients

coefplot(m1,predictors=c("PercentPremiumSeats","PitchDifference","WidthDifference"))

Its clear from the graph that Percentage of Premium Seats is not significant as it passes through zero.

Compare the actual Relative Price with the fitted values given by the OLS model

The actual relative price are:

airlines$PriceRelative
##   [1] 0.38 0.38 0.38 0.38 0.67 0.67 0.67 1.03 1.03 0.75 0.75 0.56 0.26 0.52
##  [15] 0.52 0.52 0.38 0.38 0.38 0.34 0.34 0.34 0.33 0.33 0.33 0.35 0.33 0.33
##  [29] 0.34 0.34 0.34 0.42 0.42 0.42 0.42 0.65 0.65 0.65 0.24 0.24 0.24 0.24
##  [43] 0.17 0.17 0.17 0.08 0.08 0.08 0.52 0.52 0.52 1.03 0.36 0.36 0.36 0.34
##  [57] 0.34 0.34 0.21 0.21 0.61 0.73 0.73 0.73 0.73 0.39 0.39 0.39 0.39 0.26
##  [71] 0.26 0.26 0.10 0.09 0.08 0.07 0.07 0.07 0.04 0.04 0.03 1.07 1.07 1.07
##  [85] 1.07 0.40 0.40 0.40 0.40 0.48 0.48 0.48 0.48 0.33 0.33 0.33 0.26 0.09
##  [99] 0.49 0.49 0.49 0.49 0.91 0.91 0.91 0.91 0.47 0.47 0.47 1.27 1.27 0.36
## [113] 0.06 0.10 0.10 0.04 0.11 0.11 0.08 0.09 0.05 0.05 0.11 0.14 0.17 0.16
## [127] 0.15 0.07 0.17 0.18 0.14 0.13 0.16 0.18 0.18 0.25 0.20 0.26 0.19 0.23
## [141] 0.23 0.30 0.30 0.30 0.25 0.29 0.29 0.29 0.40 0.31 0.33 0.13 0.10 0.09
## [155] 0.06 1.82 1.82 1.82 1.82 1.73 1.73 1.73 1.38 0.97 0.97 0.97 0.97 0.91
## [169] 0.91 0.91 0.91 0.84 0.56 0.51 0.51 0.51 0.51 0.50 0.49 0.40 0.40 0.40
## [183] 0.40 0.26 0.46 0.46 0.38 0.38 0.38 0.30 1.08 1.08 1.08 1.08 1.03 1.03
## [197] 1.03 1.03 0.84 0.84 0.84 0.49 0.49 0.41 0.41 0.41 0.41 0.26 0.10 0.10
## [211] 0.10 1.56 1.17 0.63 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08
## [225] 0.08 0.07 0.07 0.07 0.07 0.07 0.04 0.03 0.03 0.03 0.03 0.03 0.03 0.03
## [239] 0.03 1.13 1.13 0.26 0.45 0.45 0.45 0.36 0.36 0.36 0.36 0.98 0.98 0.98
## [253] 0.33 0.33 0.33 0.33 0.36 0.36 0.36 1.13 0.42 0.42 0.42 0.40 0.40 0.40
## [267] 0.80 0.07 0.07 0.07 1.11 1.11 0.91 0.20 0.80 0.17 0.17 0.17 0.21 0.57
## [281] 0.14 0.14 0.12 0.12 0.12 0.11 0.11 0.11 0.11 0.11 0.11 0.10 0.10 0.10
## [295] 0.09 0.09 0.08 0.08 0.08 0.07 0.07 0.05 0.05 0.05 0.04 0.04 0.04 1.50
## [309] 0.96 0.82 0.42 0.42 0.40 0.38 1.11 0.83 0.83 0.77 0.60 0.60 0.60 0.55
## [323] 0.48 0.48 0.13 0.13 0.13 0.13 0.13 0.13 0.10 0.10 0.10 0.10 0.09 0.09
## [337] 0.09 0.09 0.36 0.36 0.36 0.08 0.07 0.07 0.07 0.07 0.04 0.04 0.04 0.03
## [351] 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03
## [365] 0.03 0.03 1.39 1.39 1.39 0.14 0.14 0.14 0.77 0.48 0.48 0.04 0.52 0.37
## [379] 1.89 1.89 1.89 1.87 1.67 1.64 1.53 1.29 1.26 1.26 1.26 1.11 1.11 1.11
## [393] 1.09 1.06 1.04 1.04 0.91 0.81 0.79 0.74 0.74 0.74 0.74 0.50 0.17 1.64
## [407] 1.64 1.44 0.56 0.99 0.99 0.99 0.99 0.99 0.99 0.99 0.99 0.61 0.61 0.61
## [421] 0.61 0.61 0.61 0.61 0.61 1.16 1.16 0.08 0.08 0.07 0.07 0.07 0.04 0.04
## [435] 0.04 0.04 0.03 0.03 0.02 1.71 1.68 1.68 1.30 1.30 1.30 1.30 1.22 1.07
## [449] 0.77 0.77 0.77 0.65 0.60 0.58 0.45 0.45 0.38 0.12

Price predicted by the OLS model are:

options(digits=2)
fitted(m1)
##      1      2      3      4      5      6      7      8      9     10 
## 0.3831 0.3831 0.3831 0.3831 0.3831 0.3831 0.3831 0.3831 0.3831 0.3831 
##     11     12     13     14     15     16     17     18     19     20 
## 0.3831 0.3831 0.3831 0.3831 0.3831 0.3831 0.3831 0.3831 0.3831 0.3831 
##     21     22     23     24     25     26     27     28     29     30 
## 0.3831 0.3831 0.3831 0.3831 0.3831 0.3831 0.3831 0.3831 0.3831 0.3831 
##     31     32     33     34     35     36     37     38     39     40 
## 0.3831 0.3831 0.3831 0.3831 0.3831 0.3831 0.3831 0.3831 0.3831 0.3831 
##     41     42     43     44     45     46     47     48     49     50 
## 0.3831 0.3831 0.3831 0.3831 0.3831 0.3831 0.3831 0.3831 0.3831 0.3831 
##     51     52     53     54     55     56     57     58     59     60 
## 0.3831 0.3900 0.3900 0.3900 0.3900 0.3900 0.3900 0.3900 0.3900 0.3900 
##     61     62     63     64     65     66     67     68     69     70 
## 0.3900 0.6163 0.6163 0.6163 0.6163 0.6163 0.6163 0.6163 0.6163 0.6163 
##     71     72     73     74     75     76     77     78     79     80 
## 0.6163 0.6163 0.6163 0.0446 0.0446 0.0446 0.0446 0.0446 0.0446 0.0446 
##     81     82     83     84     85     86     87     88     89     90 
## 0.0446 0.4175 0.4175 0.4175 0.4175 0.4175 0.4175 0.4175 0.4175 0.9363 
##     91     92     93     94     95     96     97     98     99    100 
## 0.9363 0.9363 0.9363 0.9363 0.9363 0.9363 0.9363 0.0028 0.4369 0.4369 
##    101    102    103    104    105    106    107    108    109    110 
## 0.4369 0.4369 0.4369 0.4369 0.4369 0.4369 0.4369 0.4369 0.4369 0.4369 
##    111    112    113    114    115    116    117    118    119    120 
## 0.4369 0.4369 0.4369 0.4369 0.4369 0.4369 0.4369 0.4369 0.4369 0.4369 
##    121    122    123    124    125    126    127    128    129    130 
## 0.4369 0.4369 0.4369 0.4369 0.4369 0.4369 0.4369 0.4369 0.4369 0.4369 
##    131    132    133    134    135    136    137    138    139    140 
## 0.4369 0.4369 0.4369 0.4369 0.4369 0.4369 0.4369 0.4369 0.4369 0.4369 
##    141    142    143    144    145    146    147    148    149    150 
## 0.4369 0.4369 0.4369 0.4369 0.4369 0.4369 0.4369 0.4369 0.4369 0.4390 
##    151    152    153    154    155    156    157    158    159    160 
## 0.4369 0.0787 0.0787 0.0787 0.0787 0.6484 0.6484 0.6484 0.6484 0.6484 
##    161    162    163    164    165    166    167    168    169    170 
## 0.6484 0.6484 0.6484 0.6487 0.6487 0.6487 0.6487 0.6484 0.6484 0.6484 
##    171    172    173    174    175    176    177    178    179    180 
## 0.6484 0.6484 0.6484 0.6487 0.6487 0.6487 0.6487 0.6484 0.6484 0.6484 
##    181    182    183    184    185    186    187    188    189    190 
## 0.6484 0.6484 0.6484 0.6484 0.6542 0.6542 0.6542 0.6542 0.6542 0.6542 
##    191    192    193    194    195    196    197    198    199    200 
## 0.6542 0.6542 0.6542 0.6542 0.6542 0.6542 0.6542 0.6542 0.6542 0.6542 
##    201    202    203    204    205    206    207    208    209    210 
## 0.6542 0.6542 0.6542 0.6542 0.6542 0.6542 0.6542 0.6542 0.6542 0.6542 
##    211    212    213    214    215    216    217    218    219    220 
## 0.6542 0.3888 0.3888 0.3888 0.3888 0.3888 0.3888 0.3888 0.3888 0.3888 
##    221    222    223    224    225    226    227    228    229    230 
## 0.3888 0.3888 0.3888 0.3888 0.3888 0.3888 0.3888 0.3888 0.3888 0.3888 
##    231    232    233    234    235    236    237    238    239    240 
## 0.3888 0.3888 0.3888 0.3888 0.3888 0.3888 0.3888 0.3888 0.3888 0.4511 
##    241    242    243    244    245    246    247    248    249    250 
## 0.4511 0.4511 0.4511 0.4511 0.4511 0.4511 0.4511 0.4511 0.4511 0.4511 
##    251    252    253    254    255    256    257    258    259    260 
## 0.4511 0.4511 0.4511 0.4511 0.4511 0.4511 0.4511 0.4511 0.4511 0.4511 
##    261    262    263    264    265    266    267    268    269    270 
## 0.4511 0.4511 0.4511 0.4511 0.4511 0.4511 0.4511 0.4511 0.4511 0.4511 
##    271    272    273    274    275    276    277    278    279    280 
## 0.4511 0.4511 0.4511 0.4511 0.4511 0.4511 0.4511 0.4511 0.4511 0.4511 
##    281    282    283    284    285    286    287    288    289    290 
## 0.0256 0.0256 0.0256 0.0256 0.0256 0.0866 0.0866 0.0866 0.0256 0.0256 
##    291    292    293    294    295    296    297    298    299    300 
## 0.0256 0.0866 0.0256 0.0256 0.0238 0.0225 0.0225 0.0238 0.0238 0.0256 
##    301    302    303    304    305    306    307    308    309    310 
## 0.0238 0.0225 0.0225 0.0256 0.0238 0.0225 0.0256 0.3888 0.3888 0.3888 
##    311    312    313    314    315    316    317    318    319    320 
## 0.3888 0.3888 0.3888 0.3888 0.3847 0.3847 0.3847 0.3847 0.3847 0.3847 
##    321    322    323    324    325    326    327    328    329    330 
## 0.3847 0.3847 0.3847 0.3847 0.3847 0.3847 0.3847 0.3847 0.3847 0.3847 
##    331    332    333    334    335    336    337    338    339    340 
## 0.3847 0.3847 0.3847 0.3847 0.3847 0.3847 0.3847 0.3847 0.4948 0.4948 
##    341    342    343    344    345    346    347    348    349    350 
## 0.4948 0.4948 0.4948 0.4948 0.4948 0.4948 0.4948 0.4948 0.4948 0.4948 
##    351    352    353    354    355    356    357    358    359    360 
## 0.4948 0.4948 0.4948 0.4958 0.4958 0.4958 0.4958 0.4948 0.4948 0.4948 
##    361    362    363    364    365    366    367    368    369    370 
## 0.4958 0.4958 0.4948 0.4948 0.4948 0.4948 0.4645 0.4645 0.4645 0.4645 
##    371    372    373    374    375    376    377    378    379    380 
## 0.4645 0.4645 0.4645 0.4645 0.4645 0.4645 0.4645 0.4645 0.9677 0.9677 
##    381    382    383    384    385    386    387    388    389    390 
## 0.9677 0.9677 0.9677 0.9677 0.9677 0.9677 0.9677 0.9677 0.9677 0.9677 
##    391    392    393    394    395    396    397    398    399    400 
## 0.9677 0.9677 0.9677 0.9677 0.9677 0.9677 0.9677 0.9677 0.9677 0.9677 
##    401    402    403    404    405    406    407    408    409    410 
## 0.9677 0.9677 0.9677 0.9677 0.9677 0.5080 0.5080 0.5080 0.5080 0.4046 
##    411    412    413    414    415    416    417    418    419    420 
## 0.4046 0.4046 0.4046 0.4046 0.4046 0.4046 0.4046 0.4046 0.4046 0.4046 
##    421    422    423    424    425    426    427    428    429    430 
## 0.4046 0.4046 0.4046 0.4046 0.4046 0.4095 0.4095 0.4095 0.4095 0.4095 
##    431    432    433    434    435    436    437    438    439    440 
## 0.4095 0.4095 0.4095 0.4095 0.4095 0.4095 0.4095 0.4095 0.4095 1.0064 
##    441    442    443    444    445    446    447    448    449    450 
## 1.0064 1.0064 1.0064 1.0064 1.0064 1.0064 1.0064 1.0064 1.0064 1.0064 
##    451    452    453    454    455    456    457    458 
## 1.0064 1.0064 1.0064 1.0064 1.0064 1.0064 1.0064 1.0064

Comparision of the Actual and Relative Prices

predictedPrice=data.frame(fitted(m1))
actualPrice=data.frame(airlines$PriceRelative)
priceComparision=cbind(actualPrice,predictedPrice)
priceComparision
##     airlines.PriceRelative fitted.m1.
## 1                     0.38     0.3831
## 2                     0.38     0.3831
## 3                     0.38     0.3831
## 4                     0.38     0.3831
## 5                     0.67     0.3831
## 6                     0.67     0.3831
## 7                     0.67     0.3831
## 8                     1.03     0.3831
## 9                     1.03     0.3831
## 10                    0.75     0.3831
## 11                    0.75     0.3831
## 12                    0.56     0.3831
## 13                    0.26     0.3831
## 14                    0.52     0.3831
## 15                    0.52     0.3831
## 16                    0.52     0.3831
## 17                    0.38     0.3831
## 18                    0.38     0.3831
## 19                    0.38     0.3831
## 20                    0.34     0.3831
## 21                    0.34     0.3831
## 22                    0.34     0.3831
## 23                    0.33     0.3831
## 24                    0.33     0.3831
## 25                    0.33     0.3831
## 26                    0.35     0.3831
## 27                    0.33     0.3831
## 28                    0.33     0.3831
## 29                    0.34     0.3831
## 30                    0.34     0.3831
## 31                    0.34     0.3831
## 32                    0.42     0.3831
## 33                    0.42     0.3831
## 34                    0.42     0.3831
## 35                    0.42     0.3831
## 36                    0.65     0.3831
## 37                    0.65     0.3831
## 38                    0.65     0.3831
## 39                    0.24     0.3831
## 40                    0.24     0.3831
## 41                    0.24     0.3831
## 42                    0.24     0.3831
## 43                    0.17     0.3831
## 44                    0.17     0.3831
## 45                    0.17     0.3831
## 46                    0.08     0.3831
## 47                    0.08     0.3831
## 48                    0.08     0.3831
## 49                    0.52     0.3831
## 50                    0.52     0.3831
## 51                    0.52     0.3831
## 52                    1.03     0.3900
## 53                    0.36     0.3900
## 54                    0.36     0.3900
## 55                    0.36     0.3900
## 56                    0.34     0.3900
## 57                    0.34     0.3900
## 58                    0.34     0.3900
## 59                    0.21     0.3900
## 60                    0.21     0.3900
## 61                    0.61     0.3900
## 62                    0.73     0.6163
## 63                    0.73     0.6163
## 64                    0.73     0.6163
## 65                    0.73     0.6163
## 66                    0.39     0.6163
## 67                    0.39     0.6163
## 68                    0.39     0.6163
## 69                    0.39     0.6163
## 70                    0.26     0.6163
## 71                    0.26     0.6163
## 72                    0.26     0.6163
## 73                    0.10     0.6163
## 74                    0.09     0.0446
## 75                    0.08     0.0446
## 76                    0.07     0.0446
## 77                    0.07     0.0446
## 78                    0.07     0.0446
## 79                    0.04     0.0446
## 80                    0.04     0.0446
## 81                    0.03     0.0446
## 82                    1.07     0.4175
## 83                    1.07     0.4175
## 84                    1.07     0.4175
## 85                    1.07     0.4175
## 86                    0.40     0.4175
## 87                    0.40     0.4175
## 88                    0.40     0.4175
## 89                    0.40     0.4175
## 90                    0.48     0.9363
## 91                    0.48     0.9363
## 92                    0.48     0.9363
## 93                    0.48     0.9363
## 94                    0.33     0.9363
## 95                    0.33     0.9363
## 96                    0.33     0.9363
## 97                    0.26     0.9363
## 98                    0.09     0.0028
## 99                    0.49     0.4369
## 100                   0.49     0.4369
## 101                   0.49     0.4369
## 102                   0.49     0.4369
## 103                   0.91     0.4369
## 104                   0.91     0.4369
## 105                   0.91     0.4369
## 106                   0.91     0.4369
## 107                   0.47     0.4369
## 108                   0.47     0.4369
## 109                   0.47     0.4369
## 110                   1.27     0.4369
## 111                   1.27     0.4369
## 112                   0.36     0.4369
## 113                   0.06     0.4369
## 114                   0.10     0.4369
## 115                   0.10     0.4369
## 116                   0.04     0.4369
## 117                   0.11     0.4369
## 118                   0.11     0.4369
## 119                   0.08     0.4369
## 120                   0.09     0.4369
## 121                   0.05     0.4369
## 122                   0.05     0.4369
## 123                   0.11     0.4369
## 124                   0.14     0.4369
## 125                   0.17     0.4369
## 126                   0.16     0.4369
## 127                   0.15     0.4369
## 128                   0.07     0.4369
## 129                   0.17     0.4369
## 130                   0.18     0.4369
## 131                   0.14     0.4369
## 132                   0.13     0.4369
## 133                   0.16     0.4369
## 134                   0.18     0.4369
## 135                   0.18     0.4369
## 136                   0.25     0.4369
## 137                   0.20     0.4369
## 138                   0.26     0.4369
## 139                   0.19     0.4369
## 140                   0.23     0.4369
## 141                   0.23     0.4369
## 142                   0.30     0.4369
## 143                   0.30     0.4369
## 144                   0.30     0.4369
## 145                   0.25     0.4369
## 146                   0.29     0.4369
## 147                   0.29     0.4369
## 148                   0.29     0.4369
## 149                   0.40     0.4369
## 150                   0.31     0.4390
## 151                   0.33     0.4369
## 152                   0.13     0.0787
## 153                   0.10     0.0787
## 154                   0.09     0.0787
## 155                   0.06     0.0787
## 156                   1.82     0.6484
## 157                   1.82     0.6484
## 158                   1.82     0.6484
## 159                   1.82     0.6484
## 160                   1.73     0.6484
## 161                   1.73     0.6484
## 162                   1.73     0.6484
## 163                   1.38     0.6484
## 164                   0.97     0.6487
## 165                   0.97     0.6487
## 166                   0.97     0.6487
## 167                   0.97     0.6487
## 168                   0.91     0.6484
## 169                   0.91     0.6484
## 170                   0.91     0.6484
## 171                   0.91     0.6484
## 172                   0.84     0.6484
## 173                   0.56     0.6484
## 174                   0.51     0.6487
## 175                   0.51     0.6487
## 176                   0.51     0.6487
## 177                   0.51     0.6487
## 178                   0.50     0.6484
## 179                   0.49     0.6484
## 180                   0.40     0.6484
## 181                   0.40     0.6484
## 182                   0.40     0.6484
## 183                   0.40     0.6484
## 184                   0.26     0.6484
## 185                   0.46     0.6542
## 186                   0.46     0.6542
## 187                   0.38     0.6542
## 188                   0.38     0.6542
## 189                   0.38     0.6542
## 190                   0.30     0.6542
## 191                   1.08     0.6542
## 192                   1.08     0.6542
## 193                   1.08     0.6542
## 194                   1.08     0.6542
## 195                   1.03     0.6542
## 196                   1.03     0.6542
## 197                   1.03     0.6542
## 198                   1.03     0.6542
## 199                   0.84     0.6542
## 200                   0.84     0.6542
## 201                   0.84     0.6542
## 202                   0.49     0.6542
## 203                   0.49     0.6542
## 204                   0.41     0.6542
## 205                   0.41     0.6542
## 206                   0.41     0.6542
## 207                   0.41     0.6542
## 208                   0.26     0.6542
## 209                   0.10     0.6542
## 210                   0.10     0.6542
## 211                   0.10     0.6542
## 212                   1.56     0.3888
## 213                   1.17     0.3888
## 214                   0.63     0.3888
## 215                   0.08     0.3888
## 216                   0.08     0.3888
## 217                   0.08     0.3888
## 218                   0.08     0.3888
## 219                   0.08     0.3888
## 220                   0.08     0.3888
## 221                   0.08     0.3888
## 222                   0.08     0.3888
## 223                   0.08     0.3888
## 224                   0.08     0.3888
## 225                   0.08     0.3888
## 226                   0.07     0.3888
## 227                   0.07     0.3888
## 228                   0.07     0.3888
## 229                   0.07     0.3888
## 230                   0.07     0.3888
## 231                   0.04     0.3888
## 232                   0.03     0.3888
## 233                   0.03     0.3888
## 234                   0.03     0.3888
## 235                   0.03     0.3888
## 236                   0.03     0.3888
## 237                   0.03     0.3888
## 238                   0.03     0.3888
## 239                   0.03     0.3888
## 240                   1.13     0.4511
## 241                   1.13     0.4511
## 242                   0.26     0.4511
## 243                   0.45     0.4511
## 244                   0.45     0.4511
## 245                   0.45     0.4511
## 246                   0.36     0.4511
## 247                   0.36     0.4511
## 248                   0.36     0.4511
## 249                   0.36     0.4511
## 250                   0.98     0.4511
## 251                   0.98     0.4511
## 252                   0.98     0.4511
## 253                   0.33     0.4511
## 254                   0.33     0.4511
## 255                   0.33     0.4511
## 256                   0.33     0.4511
## 257                   0.36     0.4511
## 258                   0.36     0.4511
## 259                   0.36     0.4511
## 260                   1.13     0.4511
## 261                   0.42     0.4511
## 262                   0.42     0.4511
## 263                   0.42     0.4511
## 264                   0.40     0.4511
## 265                   0.40     0.4511
## 266                   0.40     0.4511
## 267                   0.80     0.4511
## 268                   0.07     0.4511
## 269                   0.07     0.4511
## 270                   0.07     0.4511
## 271                   1.11     0.4511
## 272                   1.11     0.4511
## 273                   0.91     0.4511
## 274                   0.20     0.4511
## 275                   0.80     0.4511
## 276                   0.17     0.4511
## 277                   0.17     0.4511
## 278                   0.17     0.4511
## 279                   0.21     0.4511
## 280                   0.57     0.4511
## 281                   0.14     0.0256
## 282                   0.14     0.0256
## 283                   0.12     0.0256
## 284                   0.12     0.0256
## 285                   0.12     0.0256
## 286                   0.11     0.0866
## 287                   0.11     0.0866
## 288                   0.11     0.0866
## 289                   0.11     0.0256
## 290                   0.11     0.0256
## 291                   0.11     0.0256
## 292                   0.10     0.0866
## 293                   0.10     0.0256
## 294                   0.10     0.0256
## 295                   0.09     0.0238
## 296                   0.09     0.0225
## 297                   0.08     0.0225
## 298                   0.08     0.0238
## 299                   0.08     0.0238
## 300                   0.07     0.0256
## 301                   0.07     0.0238
## 302                   0.05     0.0225
## 303                   0.05     0.0225
## 304                   0.05     0.0256
## 305                   0.04     0.0238
## 306                   0.04     0.0225
## 307                   0.04     0.0256
## 308                   1.50     0.3888
## 309                   0.96     0.3888
## 310                   0.82     0.3888
## 311                   0.42     0.3888
## 312                   0.42     0.3888
## 313                   0.40     0.3888
## 314                   0.38     0.3888
## 315                   1.11     0.3847
## 316                   0.83     0.3847
## 317                   0.83     0.3847
## 318                   0.77     0.3847
## 319                   0.60     0.3847
## 320                   0.60     0.3847
## 321                   0.60     0.3847
## 322                   0.55     0.3847
## 323                   0.48     0.3847
## 324                   0.48     0.3847
## 325                   0.13     0.3847
## 326                   0.13     0.3847
## 327                   0.13     0.3847
## 328                   0.13     0.3847
## 329                   0.13     0.3847
## 330                   0.13     0.3847
## 331                   0.10     0.3847
## 332                   0.10     0.3847
## 333                   0.10     0.3847
## 334                   0.10     0.3847
## 335                   0.09     0.3847
## 336                   0.09     0.3847
## 337                   0.09     0.3847
## 338                   0.09     0.3847
## 339                   0.36     0.4948
## 340                   0.36     0.4948
## 341                   0.36     0.4948
## 342                   0.08     0.4948
## 343                   0.07     0.4948
## 344                   0.07     0.4948
## 345                   0.07     0.4948
## 346                   0.07     0.4948
## 347                   0.04     0.4948
## 348                   0.04     0.4948
## 349                   0.04     0.4948
## 350                   0.03     0.4948
## 351                   0.03     0.4948
## 352                   0.03     0.4948
## 353                   0.03     0.4948
## 354                   0.03     0.4958
## 355                   0.03     0.4958
## 356                   0.03     0.4958
## 357                   0.03     0.4958
## 358                   0.03     0.4948
## 359                   0.03     0.4948
## 360                   0.03     0.4948
## 361                   0.03     0.4958
## 362                   0.03     0.4958
## 363                   0.03     0.4948
## 364                   0.03     0.4948
## 365                   0.03     0.4948
## 366                   0.03     0.4948
## 367                   1.39     0.4645
## 368                   1.39     0.4645
## 369                   1.39     0.4645
## 370                   0.14     0.4645
## 371                   0.14     0.4645
## 372                   0.14     0.4645
## 373                   0.77     0.4645
## 374                   0.48     0.4645
## 375                   0.48     0.4645
## 376                   0.04     0.4645
## 377                   0.52     0.4645
## 378                   0.37     0.4645
## 379                   1.89     0.9677
## 380                   1.89     0.9677
## 381                   1.89     0.9677
## 382                   1.87     0.9677
## 383                   1.67     0.9677
## 384                   1.64     0.9677
## 385                   1.53     0.9677
## 386                   1.29     0.9677
## 387                   1.26     0.9677
## 388                   1.26     0.9677
## 389                   1.26     0.9677
## 390                   1.11     0.9677
## 391                   1.11     0.9677
## 392                   1.11     0.9677
## 393                   1.09     0.9677
## 394                   1.06     0.9677
## 395                   1.04     0.9677
## 396                   1.04     0.9677
## 397                   0.91     0.9677
## 398                   0.81     0.9677
## 399                   0.79     0.9677
## 400                   0.74     0.9677
## 401                   0.74     0.9677
## 402                   0.74     0.9677
## 403                   0.74     0.9677
## 404                   0.50     0.9677
## 405                   0.17     0.9677
## 406                   1.64     0.5080
## 407                   1.64     0.5080
## 408                   1.44     0.5080
## 409                   0.56     0.5080
## 410                   0.99     0.4046
## 411                   0.99     0.4046
## 412                   0.99     0.4046
## 413                   0.99     0.4046
## 414                   0.99     0.4046
## 415                   0.99     0.4046
## 416                   0.99     0.4046
## 417                   0.99     0.4046
## 418                   0.61     0.4046
## 419                   0.61     0.4046
## 420                   0.61     0.4046
## 421                   0.61     0.4046
## 422                   0.61     0.4046
## 423                   0.61     0.4046
## 424                   0.61     0.4046
## 425                   0.61     0.4046
## 426                   1.16     0.4095
## 427                   1.16     0.4095
## 428                   0.08     0.4095
## 429                   0.08     0.4095
## 430                   0.07     0.4095
## 431                   0.07     0.4095
## 432                   0.07     0.4095
## 433                   0.04     0.4095
## 434                   0.04     0.4095
## 435                   0.04     0.4095
## 436                   0.04     0.4095
## 437                   0.03     0.4095
## 438                   0.03     0.4095
## 439                   0.02     0.4095
## 440                   1.71     1.0064
## 441                   1.68     1.0064
## 442                   1.68     1.0064
## 443                   1.30     1.0064
## 444                   1.30     1.0064
## 445                   1.30     1.0064
## 446                   1.30     1.0064
## 447                   1.22     1.0064
## 448                   1.07     1.0064
## 449                   0.77     1.0064
## 450                   0.77     1.0064
## 451                   0.77     1.0064
## 452                   0.65     1.0064
## 453                   0.60     1.0064
## 454                   0.58     1.0064
## 455                   0.45     1.0064
## 456                   0.45     1.0064
## 457                   0.38     1.0064
## 458                   0.12     1.0064

Conclusion

The difference in seat pitch is an important factor which determines the difference in price of Economy And Premium Economy seats. For every one inch increase in Pitch difference, relative price increases by 0.064 units.

The difference in seat width is an important factor which determines the difference in price of Economy And Premium Economy seats. For every one inch increase in Width difference, relative price increases by 0.10 units.

Our hypothesis:" The difference of prices of economic and premium economic seats is affected by percentage of premium seats, difference in pitch and difference in width of the seats" is wrong as through the regression analysis

“The diffence in prices of economy and premium economy seats is affected by pitch difference and width diffence”.

THANK YOU